The EEB Spring Symposium will be on Saturday, March 31st.
This is an all day event where graduate students get a chance to present their research to other graduates and faculty in the department. Regardless of your research level, this symposium provides an opportunity to present project ideas and/or results in a low-stress atmosphere, and obtain valuable feedback from grads and faculty. Because this is an all day event, lunch and snacks will be provided by funds requested from the GSS by our graduate student GSS senators. Grads, please consider giving a talk.

Molecular phylogenetic methods often are based purely on the linear sequence of nucleotides for the region of interest. Methods that explore additional facets of sequence data include models of codon evolution for protein coding regions and doublet models that account for covarying sites. I have developed a method that extracts further phylogenetically-informative data from the nuclear internal transcribed spacer (ITS) region, based on predicted models of ITS secondary structure. Like their flanking ribosomal genes, the ITS regions (ITS-1 and ITS-2) have secondary structures ('stems' and 'loops') that are conserved across taxonomic groups as divergent as algae and angiosperms. In the method presented, the seven conserved structural regions of ITS (three from ITS-1 and four from ITS-2) were encoded for their nucleotide composition and pairwise alignment type (match or mismatch). Data for different taxa were aligned to each othe under the primary criterion of structural similarity, which differed from the traditional, phenetic alignment. Rather than incurring costs simply for changes in nucleotide identity, the method penalized changes that disrupted secondary structure. Thus, by aligning sequences based on structure and assigning costs to structural changes, the method generated phylogenetic data that were nearly independent from the simple nucleotide sequences on which they were based. In an application from the family Menyanthaceae, the method substantially improved support for nodes that were ambiguous under analysis of traditionally aligned sequences.

Beth Jacobsen

Introgression between two NZ cicada species and how are periodical
cicadas periodical

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Molly Letsch

The Zoochlorella Symbiont of Anthopleura Form a Distinct Monophyletic Taxon in Trebouxiophyceae.

Does atmospheric nitrogen deposition contribute to the decline of a native nitrogen-fixing species, Desmodium cuspidatum?

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Jang K. Kim

Are Intertidal Seaweeds More Efficient at Nutrient Absorption?

Desiccation stress can determine the upper distribution limits and could enhance the uptake of nitrate and ammonium of intertidal algal species. Emersion following desiccation might stimulate several aspects of metabolism. Upper shore species may exhibit greater stimulation of N uptake following desiccation and achieve maximum uptake at higher desiccation levels. The objective of this study was to determine whether Porphyra species from different vertical elevations respond differently to the desiccation stress, in terms of nitrate uptake and growth. The intertidal species (Porphyra umbilicalis) and subtidal species (P. amplissima) were utilized in this study. Both species were cultivated at 100–150 umol m-2 s-1 light intensities, 500 uM nitrate concentration and 10 C (P. umbilicalis). Porphyra amplissima was cultivated at 15 C for three days, and P. umbilicalis was cultivated at 10 C for three weeks at a photoperiod of 12:12h L:D. Samples were exposed to air for 0, 30 min (30-50% water loss) and 2 hrs (90% water loss), 4 hrs after light exposure each day. Desiccation was more stressful to the subtidal species, P. amplissima, than to the intertidal species, P. umbilicalis. When tissues were exposed for 2 hrs daily, P. amplissima lost weight and pigments, while the growth rate of P. umbilicalis dropped by only 30% compared with that of continually submerged blades. Nitrate uptake rate of subtidal P. amplissima was only 73% (30-50% water loss) and 62% (90% water loss) of that of continually submerged tissue. Nitrate uptake rates of P. umbilicalis were not significantly different in each treatment. These results suggest that species in the intertidal zone, which have longer exposure times, may have higher time-use efficiency than the subtidal species in terms of nitrate uptake. This indicates a possible correlation between nitrate uptake and observed vertical distribution patterns.

Adam Wilson

The Fire-Weather relationship in the South African Fynbos: Implications under Climate Change

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Roberta Engel

Origins of pseudoscorpion lineages endemic to the outcrops of southwestern Australia

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Susan Letcher

Methods for evaluating ecological similarity in large multivariate data sets: an example using forest succession data from northeastern Costa Rica

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Carrie Fyler

Erection of a new genus: A total evidence approach to tapeworm Systematics

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Karolina Fucikova

New Algal Species Records for the Great Smoky Mountains National Park, U.S.A.

The Great Smoky Mountains National Park harbors a remarkable biodiversity. Within the All Taxa Biodiversity Inventory (ATBI), a project that has been in progress in the park since 1997, 976 algal taxa have been reported to this day. This number includes a few old historical records from the 1940s, as well as hundreds of taxa reported by the algal Taxonomic Working Group (TWiG) of the ATBI. From the total of 976 taxa, 392 have been added since the last published species record list (2004). Ranges of several algal taxa have been extended as a result of this work. In addition, some new species of diatoms (Bacillariophyta), blue-green algae (Cyanobacteria), green algae (Chlorophyta), and conjugating green algae (Charophyta) have been described. Even more taxa, ca. 50, have not been identified to species level with certainty, and are therefore putative new species as well.

Juan Carlos Villarreal

Toward a phylogeny of the Nothoceros/Megaceros alliance and the origin of the North American Endemic M. aenigmaticus